Hvac

HVAC is the abbreviation for the three aspects of climate control: heating, ventilation, and air conditioning. The term is also commonly used to refer to an HVAC system, the mechanism by which these functions are delivered and controlled within the home or office.

Heating, Ventilation, and Air Conditioning

Heating is the process of pumping hot air derived from a boiler or furnace through a series of ducts within a building. These ducts are themselves connected to wall- or floor-mounted radiators, which distribute the heat through the building by means of convection, the natural rising of hot air.

Ventilation is concerned with neither heat nor cold but instead works to maintain a supply of fresh air into a building, which is both a sanitary and a safety precaution and helps to reduce unpleasant odors. It can also be used to regulate humidity. Ventilation can be natural (i.e. produced without mechanical assistance) or assisted by means of fans.

Air-conditioning can technically refer to any aspect of climate control but is commonly associated with refrigeration, which operates by channeling cold, low-pressure Freon gas from a special compressor through the same large ductwork used to spread heating. Many modern air-conditioning systems are split-system units, which contain a cold-air producing mechanism within the building and a warm-air unit on the building's exterior, a design intended to isolate the noisier components and reduce the need for extensive ducts, which can often be expensive to lay in if a building has not been pre-designed for their placement.

Thermostats

HVAC systems are controlled by means of a thermostat, a mechanism by which a user can automatically regulate these complex processes by simply selecting a desired temperature. Formerly, thermostats worked by means of temperature-sensitive metallic strips, which would expand or contract according to heat or cold and manipulate switches connected to the furnace accordingly. Modern thermostats are usually digital, with internal temperature sensors and more sophisticated transistor switches.

Maintaining an HVAC System

HVAC systems can be massive energy guzzlers if they are poorly designed, ill-maintained, or overused. It is extremely important that HVAC systems be meticulously installed to ensure that they will meet each room's individual needs without excess expenditure of energy. Regular seasonal checkups can help to ensure that heating and cooling systems are not working below expectations as a result of obstructions caused by grime, leaks in the pipes or ducts, or malfunctioning mechanisms such as fans. In addition, installing mechanical timers can help to ensure that such systems are not inadvertently left on for excessive periods.

By Matthew Ingalls